TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4410 SUBJECT: GRB 051227: Gemini observations DATE: 05/12/28 17:56:26 GMT FROM: Edo Berger at Carnegie Obs E. Berger (Carnegie Observatories) reports: "We imaged the error circle of GRB 051227 (GCNs 4397,4401) with GMOS on the Gemini-north telescope starting on 2005, Dec. 28.33 UT (13.88 hr after the burst). A total of 25 min were obtained in r-band in good seeing conditions (0.75"). Within the refined XRT position (GCN 4402) we detect source S1 (GCNs 4404,4407,4408) at coordinates (J2000): RA = 08:20:58.107 DEC= +31:55:32.01 We also detect an additional faint source about 0.7" outside of the XRT error circle (S2) which is not clearly visible in the finders provided by Malesani et al. (GCN 4407) and Bloom et al. (GCN 4408) at coordinates: RA = 08:20:57.773 DEC= +31:55:26.67 Using several nearby stars with SDSS calibration (GCN 4399) we determine that source S1 has r=24.8+/-0.15 mag, while source S2 has r=25.5+/-0.25 mag. Since previous GCNs do not provide photometry of source S1 we are unable to determine whether it has varied in brightness compared to earlier observations. A finding chart showing objects S1 and S2 is available at: http://www.ociw.edu/~eberger/grb051227-gemini.ps Further Gemini observations are planned."